First up, here’s former Democrat Congressman Paul Kanjorski of Pennsylvania, who lost his reelection bid during the Tea Party-led GOP wave in 2010, telling his constituents in 2008 this his party lied to take back Congress in 2006:

“I’ll tell you my impression. We really in this last election, when I say we…the Democrats, I think pushed it as far as we can to the end of the fleet, didn’t say it, but we implied it. That if we won the Congressional elections, we could stop the war. Now anybody was a good student of Government would know that wasn’t true. But you know, the temptation to want to win back the Congress, we sort of stretched the facts…and people ate it up.”

Which was built upon attacking a war which Democrats (including Kanjorski, for what it's worth) initially supported:

And once the left recaptured the White House, here's President Obama saying over and over again (36 times in the clip below), “If you like your plan, you can keep your plan,” knowing full well he was lying…and true believers ate it up:

And here’s Hillary in 2007 making the same boast for the plan she would enact, if she was elected president: